Dual pane "insulated glass" windows?

[BarbWire]

This is for a house in the Austin area, built 1998. The aluminum-frame windows are dual-pane. There are approximately 36 pane units in the house (either fixed, upper sash, lower sash). The original panes are dual clear glass, not Low-E.

Five of the units have significant fogging and/or condensation between the panes and need to be replaced. I will use clear glass, not Low-E as putting Low-E in 5 of 36 units is .... dumb. Summer highs in the low 100's, winter lows in the 30s, and for much of the year the window are open (so thermal efficiency/insulation isn't super important).

Two quotes, about the same ($1800 with tax). About the same turn around time. Same warranty (10yr) which is voided if solar film/tinting is put on the window (which would be highly desirable for three fixed windows).

My very shaky understanding of windows is that two components are important: (1) the spacer material (NB for rigidity and thermal transfer/bridging), and (2) the sealing method/system (NB for gas leakage/condensation). Is this correct?

Company #1: manufactured at Dallas Flat Glass, using a "dual seal system." I don't know (yet) what the spacers are made of

Company #2: manufactured at Thermotec in Georgetown TX using a "Super Seal" spacer -- but I don't know what this means for the sealing system.

School me. What should I be looking for in replacement dual-pane windows when the primary goal is no condensation in the next 5 years?

EDITED to add: I just discovered that there is a "National Fenestration Ratings Council." Who'da thunk?

 

[Sunset]

If all you are interested in is no condensation, make sure the warranty covers that. All the BS sealing talk from sales folks holds no water when the window fogs up, as the companies will refer to the warranty.

Five years is an extremely short time, windows normally can last 15 yrs pretty easily, ours are 25 yrs old and I replaced the glass in one (just the sealed glass part) and we have 4 others that should be replaced. The 8 other remaining ones are still fine.

Are they going to replace the entire window or just the glass within each window ?

 

[Mark1]

The condensation means the seal between the glass panes failed and is not likely related to low E IMO. I would go with low E even in Austin, unless you are worried the new windows might not match the old windows on the house now (low E windows likely have a slightly more mirrored appearance).

I suspect the low E will help more with your AC bill than your heat bill.

 

[BarbWire]

If all you are interested in is no condensation, make sure the warranty covers that. All the BS sealing talk from sales folks holds no water when the window fogs up, as the companies will refer to the warranty.

Five years is an extremely short time, windows normally can last 15 yrs pretty easily, ours are 25 yrs old and I replaced the glass in one (just the sealed glass part) and we have 4 others that should be replaced. The 8 other remaining ones are still fine.

Are they going to replace the entire window or just the glass within each window ?

Most of the glass in the house (24 years old is fine -- or it has leaked but the condensation is barely visible around the mullions). The ones that have quite visibly failed are the two lower sashes in the kitchen (northern light) and upper level "arch" windows in the living room (intense eastern sun). Oddly, the single hung windows below the arch windows have not noticeably failed.

One concern about the warranty is that if solar film is put on the arch windows (very necessary in the summer) that voids the glazier's 10 year warranty. The solar film company may pick up the warranty, but that is something to ask.

The glaziers will be replacing just the glass (and mullions); the windows themselves are fine.

The condensation means the seal between the glass panes failed and is not likely related to low E IMO. I would go with low E even in Austin, unless you are worried the new windows might not match the old windows on the house now (low E windows likely have a slightly more mirrored appearance).

I suspect the low E will help more with your AC bill than your heat bill.

Good points, but I'll stick with clear glass: I don't see how changing five of 5 of 36 windows would have a significant effect on the AC bill (which is already quote low because I keep the house at 82* if the AC is running). If I were replacing more glass and ran the HVAC system more, then lowE would be the way to go.


So really my biggest concern is condensation in the next 5 years -- as I hope to sell the house in the next 1-4 years!

 

[Scrapr]

It's a long shot but look to see if the manufacturer will replace the fogged panels. We have done it in 2 different homes. In Oregon it's a lifetime warranty on the seal. The first time I had to pressure them as the original company went BK. And reformed under the same name

 

[BarbWire]

It's a long shot but look to see if the manufacturer will replace the fogged panels. We have done it in 2 different homes. In Oregon it's a lifetime warranty on the seal. The first time I had to pressure them as the original company went BK. And reformed under the same name

That's good advice. Alas, as the fifth owner of this house, I don't know who the original manufacturer is. For the replacement, both glazier companies say "10 year warranty on the unit, 1 year warranty on labor." And warranties voided by adding solar film.

I'll be on the phone tomorrow with both companies and the solar film company. Right now I'm in the position of having quotes that are comparable in cost, but I have no idea how to compare the "product" that they are selling. They're not forthcoming with information (maybe no one asks for it) and I'm clueless about how to evaluate it.


BTW, I really miss Oregon. I was there for 14 years until my high-tech job was sent to Shanghai....

 

[CRLLS]

We have a 33 year old home with very large windows that face South. Some of the windows were replaced before we bought the house 17 years ago. We did not find the name of the window mfgr anywhere. We replaced the thermopane glass in the remaining ones thru the local glass shop, not a "window company. They made them to my size. I had them installed into the original aluminum-clad wood sashes. The color of the glass is slightly off but you wouldn't know it if you weren't looking for it. They said the manufacturers change the glass formula every once in a while, which has a slight effect on the color.

With aluminum frames, I don't think the spacer style means much if both are warranted the same. I would go with the one you feel more comfortable with assuming both have been around for some time. Ask for references from several years back. not just recent customers.

 

[Sunset]

That's good advice. Alas, as the fifth owner of this house, I don't know who the original manufacturer is. .....

In a corner of the window, on the glass there is sometimes a symbol or name of the company that made the window. Look at a few windows as it's only lightly etched and sometimes fades away.

 

[Bamaman]

I had to replace about 3 fogged dual pane window glasses after about 5 years. They were installed in generic wooden windows.

I just measured and ordered the glass panes from a glass company in Atlanta. The windows had a thin aluminum piece holding the glass apart, and they were sealed with what seemed like black silicone rubber.

I broke the old glass out and easily removed the pieces. Then I scraped a sealant out of the grooves and installed the new panes with silicone sealant. It was maybe a 1/2 hour job per window.

For $1,800 quoted, you could install 5 new vinyl windows. I don't remember how much each window cost, but it was very inexpensive for the time.

I've since had cheap generic vinyl windows in 3 different homes, and not a one ever fogged up.

 

[The Cosmic Avenger]

Why do you think it wouldn't be worth it to get low-E glass only on some windows, especially if you're looking into solar film, despite it voiding the warranty? We used a special tinted glass in our sunroom roof (as opposed to the walls) since that gets a ton of sun, and when we replaced our regular windows we got low-E glass on the windows on the south side, as that's where the sun really beats down -- we had had a film applied to the same southern windows before we replaced them, and it really helped with heat transmission on sunny days.

 

[RetiredAndLovingIt]

Curious how much extra Low E glass would cost or would you have to replace the entire window frame to get it? It really works great and is darker (greenish tinit) and reflective outside during the day,. When I replaced my patio sliding door it came with low-E and I'm really happy with it. I'm going to be checking locally with a glass company to see what my options are based on your post, your quoted price is really cheap and my aluminium frames are still in good shape. Thanks for posting and be sure to let us know what you decide and how it works out for you.

 

[TripleLindy]

We’re in the DFW area so we have similar weather. I don’t know how you keep your windows open most of the year. For us, it’s either too hot, too cold or too humid to raise the windows. We actually used large picture windows in lieu of windows that open in our living room and dinette area because we never raised those windows.

We had vinyl windows from Milgard installed and are very happy with them. I can’t remember the details, but they are well-insulated and even have much better noise reduction - so much so that we don’t notice the planes in and out of DFW airport the way we used to. Our utility bills have declined significantly since replacing the builder grade aluminum windows. They have some level of tinting built in, but they’re not “green” like others I’ve seen. In more than 8 years, none of the windows have fogged.

In your post, you state that the quote is $1800. I assume you left a 0 off. If not, that’s a screaming deal for 36 windows!

 

[bloom2708]

Depending on the size of the windows, $1800 might be a reasonable quote.

We have done ~8 windows with replacement glass. There are 3 layers, 2 outside and one inside in our Hurd windows from 1998.

A local window company (small) measures the glass, orders the new sealed unit. They then disassemble the wood window, scrape out the old seal, seal and replace the glass.

It is a manual process, but cheaper than a whole new window. Each size has their own price, but they are usually $180 to $300 depending on the size. If these are larger windows, 5 x $360 ordered and installed might be reasonable.

Find a couple smaller window companies and get a few quotes.

I have also replaced 6 window cranks that were worn out/bending due to age. Those were ~$70 each. Nothing cheap with windows.

 

[kgtest]

FWIW I just had an estimate for 6 panes for the same price as you. I live in MN, with extremes of 100 degrees down to -30 degrees. Right now we get actual frost on a couple of the panes on the inside of the home during the cold months.

I used to run a glass replacement company. I am using the contractors who I used to do a lot of business with. They get their glass from a supplier in Wisconsin. There are plenty of companies who make their own glass. 10 yr warranty is probably fairly standard.

 

[cyber888]

I replaced 3 glasses in 3 windows for $378 in summer of 2021 due to the fog. Last 2 weeks, got a quote to replace 2 half-moon glass, and it is now $850 bucks (Oct. 2022)

 

[Jerry1]

If I knew I was selling my house in less than 5 years, I’d ask myself why I want to fix the windows. The fogging is basically a cosmetic issue. When I bought my house, the inspector noted two windows that were fogging up. Said I could replace but did not need to. Fast forward, 6 years and the drapes cover the windows and I don’t typically look out those two windows and I saved myself about $800. If they were on the other side of the house, looking out to our back yard, I may have thought differently. However, it’s worth asking, are you fixing them because they actually bother you or just because you don’t like the idea that they’re “broken”?

 

[Calico]

We’re in the DFW area so we have similar weather. I don’t know how you keep your windows open most of the year. For us, it’s either too hot, too cold or too humid to raise the windows. We actually used large picture windows in lieu of windows that open in our living room and dinette area because we never raised those windows.

We had vinyl windows from Milgard installed and are very happy with them. I can’t remember the details, but they are well-insulated and even have much better noise reduction - so much so that we don’t notice the planes in and out of DFW airport the way we used to. Our utility bills have declined significantly since replacing the builder grade aluminum windows. They have some level of tinting built in, but they’re not “green” like others I’ve seen. In more than 8 years, none of the windows have fogged.

In your post, you state that the quote is $1800. I assume you left a 0 off. If not, that’s a screaming deal for 36 windows!

The OP is only replacing 5 of the 36 windows.

 

[rodi]

Our granny flat has a failed double glazed window in the main (large) window in the living room. We are replacing the glass, not the window. We are going with low-E since that was what was in it - and it's in direct sun all afternoon. (West facing)

We got quotes from 3 glass companies (not window companies). All take measurements, then order replacement glass. Then take the window apart to replace the glass. They needed to physically come onsite to verify the window type and take measurements. There was a big spread in prices - the glass was pretty much the same on all three quotes - but labor varied widely. Both the quoted time and rate.

As we've replaced our windows on our main home (all but two of the original single pane are replaced - north facing window and garage window still remain) we've opted for low-E. Even in temperate San Diego (40's to 90's, but mostly 60's-70's) we noticed a big difference in our power bills when we replaced old school single pane with low-E double pane. (Not surprising). Personally, I'm a fan of low E, and my temp swings are a lot less.

 

[Masquernom]

To the OP, if you have aluminum frame windows, it probably makes almost no difference what spacer is used in the replacement glass pane unit. I expect you transfer most of your heat through the aluminum frame.

 

[txtig]

I would seriously consider replacing all of the windows in the house. The house is over 20 years old and five have already lost their seal. Others will likely begin to fail in the next few years.

A few years ago, we had the same problem in our 1993 house. Seven or eight of our aluminum frame insulated windows (28 windows total) had failed. We didn’t want the house to look like patch work with different style windows, so we elected to replace them all. It was a good opportunity to update the look of the house and improve the overall energy efficiency.

We also converted several windows from operating windows to picture windows (as a previous poster suggested) since we never opened them.

It wasn’t cheap, but at least we won’t have to deal with the inevitability of having to replace multiple windows in the near future ad they also begin to fail.

 

[Sunset]

I would seriously consider replacing all of the windows in the house. The house is over 20 years old and five have already lost their seal. Others will likely begin to fail in the next few years.
.......
It wasn’t cheap, but at least we won’t have to deal with the inevitability of having to replace multiple windows in the near future ad they also begin to fail.

I would not as I have a 60+ year old house, and only 3 windows have failed. Windows can go a LONG time before failing depending on many issues.

OP is planning to sell in 5 years, chances are 0->2 windows might fail in that time.

Replacing all , is like buying a new washer and dryer when the washer fails. Lots of people do it, but it's not needed and is more expensive than needed.

 

[Masquernom]

As I understood it, the OP is not "replacing" windows exactly. I believe they are just installing new double pane glass units into the existing aluminum window frames. That's a lot cheaper than complete replacement windows.

 

[BarbWire]

OP here: Thanks to all for the replies.

To recap: just the glass (dual pane with aluminum mullions) will be replaced in five windows; the 24 year old window frames themselves will not be replaced. In the five windows, two look like teenagers soaped them (the kitchen window lower sashes) and three have water dripping inside (three high arch windows in living room). These are aesthetic issues now and are significant enough to set off "alarm bells" in a potential buyer.

Note that several other windows apparently have leakage -- one of the estimators showed me how to look along the mullions for slight fogging. Not worth replacing since I have to really search to see it!

I never got a good explanation of either vendor's spacing and sealing technology. Both companies are well reviewed, etc. Ultimately it came down to a matter of timing -- one would have the glass in 2-3 weeks, and the other in 4-6 weeks. So that made the decision.

Regarding lowE: it would have been about $150 more per window. I'll have a conversation with the solar film company this week to find out how they will cover/take over the warranty. But that's also a problem I don't really need to face until spring.

Thanks again!

 

[BarbWire]

I replaced 3 glasses in 3 windows for $378 in summer of 2021 due to the fog. Last 2 weeks, got a quote to replace 2 half-moon glass, and it is now $850 bucks (Oct. 2022)

The company that I have selected is replacing three windows for my neighbor today. The estimator (who has "been in the glass business" for 15 years) told the neighbor that the cost of the glass units from their manufacturer in Dallas has nearly doubled in the past year. Ouch!

 

[RetiredAndLovingIt]

I'd love to see your before and after photos when they're done.
My "arch" windows are the only ones that the seals have failed on as well. They were replaced about 15 years ago and I'm pretty sure it cost me $375 total for both at the time. I doubt I'd get close to that price now.